What characterizes two-layer predictions in zone models?

Two-layer predictions in zone models are characterized by the distribution of smoke and heat within structures. These models simplify the complex behavior of smoke and heat during a fire by dividing the space into two distinct layers: a hot upper layer where smoke and hot gases accumulate and a cooler layer near the floor level where there is less heat and potentially more breathable air.

This approach allows fire investigators to better understand how smoke and heat travel through a building, which is crucial for assessing the fire's behavior, predicting how it will spread, and formulating effective strategies for fire suppression and evacuation. By focusing on these two layers, investigators can analyze conditions within a structure and make informed decisions based on how smoke and heat interact with the space and its occupants.

Understanding the distribution of smoke and heat also aids in determining the potential impact on visibility, air quality, and temperature variations throughout different areas of the building during a fire incident.